Oil leak

[Black Hole]

I have an oil leak on my new 7 that appears to be coming from the pressure sending unit which consists of a brass fitting attached to the block with two exit ports. One has a pressure transducer connected directly to it (has a press on connector with multiple pins) and the other has a fitting between it and a low oil pressure switch (I think it only had one wire connected to it).

 

I was able to move the pressure xducer fitting a few degrees, The others seemed tight (though clearance was an issue so it was a challenge to get a wrench on). After tightening it is still leaking. This is a small leak (enough for CT to not pass my DMV inspection to register the car) as it has no apparent effect on the oil level.

 

So what is the best way to seal this connector. I believe teflon tape will be a problem on the LOP as it will inhibit the ground. So what is the right type of sealant for this type of joint?

[TheDingo8MyBaby]

Teflon tape isn't meant to seal, but instead is a thread lubricant.

 

Are you sure they are NPT fittings? If so, Teflon tape should help (possibly solve the problem), but I prefer loctite 545 which is specifically intended for this purpose.

 

I wouldn't worry about the ground. The threads will shear the teflon and there will be metal to metal contact.

Edited October 31, 2016 by TheDingo8MyBaby

[Black Hole]

Thanks, I found the Loctitie 545 as well as Permatex high temperature sealant. I think i will head over to NAPA and see what they have in stock.

 

I do not believe they are all NPT, but some may be (there are a total of four potential joints to leak, I do not think it is leaking at the block.

 

Teflon tape isn't mean to seal, but instead is a thread lubricant.

 

Are you sure they are NPT fittings? If so, Teflon tape should help (possibly solve the problem), but I prefer loctite 545 which is specifically intended for this purpose.

 

I wouldn't worry about the ground. The threads will shear the teflon and there will be metal to metal contact.

[Black Hole]

One more questions; how much oil will leak out when I remove the sensors. I suspect not much as this would have to be after the oil pump so only the oil in the galley above. I am assuming i do not need to drain the sump to keep from having a mess.

[Black Hole]

I believe the oil leak is now resolved. The tightening of the fittings, transducer and LOP did not stem the leak. It appeared to be coming from either the low oil pressure switch (which screwed into an adapter between it and the brass union attached to the block) or the oil pressure xducer. There was enough oil on both that it was hard to tell which was the culprit.

 

I took them all off (left the brass union attached to the block as it did not appear to come from that junction) and used Permatex thread sealant on all the fittings. Previously the oil appears after a short drive. The fittings are now dry after 15+ miles of driving so I think this resolved it.

 

And to answer the question in the previous post, maybe a few tablespoons of oil came out when I removed the oil pressure xducer. No oil came out when i removed the LOP switch.